The present invention relates to a device for therapeutic treatment of wounds and, more particularly, to a device of this kind of the type including a dressing provided with a layer for absorbing exudates from the wound and electric supply means to circulate a current in said wound through said dressing.
Many types of dressings have been designed to absorb the exudates from a wound and to accelerate healing of the wound. One such dressing is a semi-occlusive and sterile adhesive dressing consisting of a hydrocolloid mass layer applied to a support consisting of a polyurethane film for local treatment of wounds such as leg ulcers or bed sores. The Chenxc3x4ve, France company Laboratoires URGO manufactures a dressing of this kind, which is marketed under the ALGOPLAQUE brand (registered trade mark). In contact with a wound, the hydrocolloid particles dispersed in the layer absorb the exudates, swell and form, a moist gel encouraging healing of the wound without the newly formed tissues being damaged when the dressing is renewed.
Electrotherapy of wounds is a known technique for accelerating healing. The technique consists generaly in applying two electrodes to the skin of the patient and passing an electric current between the electrodes so that the current enters a wound in the skin. The document EP-A-0 367 320 describes a wound treatment system including a dressing consisting of an electrically conductive compress, a return electrode and means for passing an electric current between the compress and the return electrode. The compress includes an electrically conductive hydrophile gel layer which can contain up to 93-96% bound water and is rendered conductive by a metallic salt. The gel layer is applied to an electrically conductive layer. An electric current flows in this layer and in the hydrophile gel layer and then in the wound before returning to the return electrode. The capacity of a gel of the above kind to absorb exudates from the wound is limited by its initial moisture content.
The object of the present invention is to provide a device for therapeutic treatment of wounds in which the capacity for absorption of exudates from the wound is maximised, while being combined with an electric treatment of the wound.
This object of the invention, along with others that will become apparent on reading the following description, is achieved with a device for therapeutic treatment of wounds of the type which includes a dressing provided with a layer for absorbing exudates from the wound and electric supply means to circulate a current in said wound, through said dressing, which device is remarkable in that said layer consists of a dry hydrophile layer which is substantially electrically non-conductive at the time it is applied on the wound, subsequent migration of exudates into the thickness of said layer controlling the activation of said electric supply means.
Said initially dry hydrophile layer is therefore used without deterioration of its capacity to absorb exudates. As will be shown later, this initially non-conductive layer becomes conductive as it becomes charged with exudates. It therefore becomes sufficiently conductive at some stage to enable xe2x80x9celectricxe2x80x9d treatment of the wound.
In this regard, according to one feature of the device in accordance with the present invention, said electric supply means include a circuit for measuring the impedance of the hydrophile layer and means responsive to said measurement falling below a predetermined threshold to command the activation of the electric supply means under nominal conditions.